@robert-hh
Thanks, yes P4 (CS) is the right pin, otherwise I would not have the reply I put you the signal as screen copy; I test also with read(2) : same result : 0 , I am not sure of a/ 10000 = 10 Mkz or 1 Mkz ? and b/threshold of the signal on Miso : I have this evening a max voltage at 3.2V : is the signal considered at "1" with 3.2V on SipY Miso pin? -
The same installation with 3.3V in Vcc was working on Arduino last week and gave me temperature's answer quickly.
best regards
William

@prx Just saw something else: the parameter bits could be wrong. from the documentation:
"bits is the width of each transfer, accepted values are 8, 16 and 32."
Error messages are sometimes off by one line.
If the device you try to talk to is a max6675, then the data size is 16 bits. If the device is just sending 12 bits, read 16 and ignore 4.
And about the data rate: according to the data sheet the max6675 can be clocked up to 5 MHz. So no need to use 9600.
Edit: 5 MHz do not work (skips a bit), but 1 MHz do,